How'd you tell your parents you were joining the military in wartime or how did your kid tell you?

So i'm enlisting in the air force. My mom doesn't want me to... she says finish school first, wait till the war is over. My dad says that I won't be able to handle it and I just need to do school and stay living at home until I'm done... It has been a year since I last had this conversation with them... their opinions is one of the reasons I dropped out of DEP last year, that and a kidney infection that landed me in the hospital. Now It's a year later and still what I want to do... how should I tell them, how did you tell you parents and how did they react... or if your a parent how did your kid tell you and how did you react... keep in mind i'm 21 but I just don't want my mom to worry about me... my mom is my heart I don't know where I would be without her!